What to make a radio/bluetooth keychain for writing to mysql database?

Question

MySQL

There is a task to create a miniature keychain with one button, by clicking on which an entry will be inserted into the database. On which platform to implement this with minimal investment?

Answer 1

Bluetooth module HC-05 . Short TX, and RX, connect to a button. Connect the second pin of the button to GND.
The program should send the value 255 to the module (actually write to the com port) and read the response.
If the response is 255, the button is released, 0 is returned - the button is pressed.
If there is no answer, there is no radio communication with the module.
There are more "beautiful" solutions, for example, write a special program for the microcontroller in a module, based on the article .